The present invention relates to regulators. More particularly, it relates to a voltage regulator for the energization of a memory module.
In the modern computer art, there are provided memory modules wherein data is stored during the computational process. In certain types of these memory modules, the modules must be continuously energized in order to preserve the data stored therein. It is, therefore, usual that, in addition to the main operating power supply of the computer system, a back-up battery is provided to supply energizing current to the memory module whenever the main power supply fails. In the previously known systems, the transfer of energization from the main power supply to the back-up power supply has involved complex switching systems, complex control systems, or both. It is further noted that in a power-down situation, whenever the main power supply has failed, it is only desired to preserve the data stored in the memory and not to manipulate that data. Accordingly, it has been found that a lower energizing voltage is required to maintain the memory during power down condition than the voltage required when the data is to be manipulated.